JPH0247605B2 - DENJIBURE EKI * KURATSUCHI - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electromagnetic brake/clutch in which the friction surfaces between the armature and the outer and inner magnetic poles are laser carburized and hardened to improve wear resistance, torque characteristics, and operating characteristics. It is.

The structure and operation of an example of a conventional electromagnetic brake will be explained with reference to the drawings. In Fig. 1, 1 is a drive shaft, 2 is a spline, 3 is a leaf spring,
4 is an armature, the spline 2 is fitted onto the drive shaft 1, and the leaf spring 3 has one end fixed to the spline 2 and the other end fixed to the armature 4. The armature 4 meshes with the spline 2 and resists the elasticity of the leaf spring 3. The spline 2 can be slid on the spline 2. 1 to 4 above form a rotating part. 5 is the lining, 6 is the magnetic pole,
6a and 6b are outer magnetic poles and inner magnetic poles, respectively;
7 is a coil, 8 is a lead wire, 9 is a fixing plate, 10 is a fixing bolt, α is a gap, coil 7 is a magnetic pole 6
It is housed in the interior and connected to a DC power source via a lead wire 8. The outer magnetic pole 6a, the lining 5, and the inner magnetic pole 6b face each other while maintaining a gap between the armature 4 and the gap α. The magnetic pole 6 is fixed to a fixed plate 9 and fixed to an external fixed body by a fixing bolt 10. 11 is a non-magnetic material for blocking the magnetic path. The above 5 to 11 form a fixing part.

In the armature magnetized electromagnetic brake configured as described above, the armature 4 is connected to the spline 2.
It is rotated by the drive shaft 1 via. When a DC voltage is applied to the coil 7 through the lead wire 8, the magnetic path φ connects the outer magnetic pole 6a, the armature 4, and the inner magnetic pole 6.
b, flows through the magnetic pole 6 through the gap α. Then, the armature 4 is attracted by the outer magnetic pole 6a and the inner magnetic pole 6b, slides on the engagement part with the spline 2 against the elasticity of the leaf spring 3, and the fixing bolt 10
Braking work is performed by friction between the outer and inner magnetic poles 6a and 6b fixed by the lining 5 and the lining 5. Lead wire 8
When the DC voltage applied to is removed, the magnetic path φ is demagnetized, and the armature 4 is released from the outer and inner magnetic poles 6a and 6b by the elasticity of the leaf spring 3, completing the braking work. The electromagnetic brake repeatedly performs such braking work.

The armature magnetized electromagnetic clutch has almost the same structure as the brake, with the only difference being that the fixed part is rotatable, so a description thereof will be omitted.

By the way, since the armature and magnetic pole of an electromagnetic brake/clutch utilize magnetic force, pure iron or low carbon steel, which has good magnetic properties, is used. However, pure iron and low carbon steel have the disadvantage of low hardness and poor wear resistance. As a result, the amount of wear on the armature and magnetic pole increases, making it unusable and shortening the life of the electromagnetic brake/clutch.
Moreover, since the amount of wear is large, the gap increases, resulting in poor torque characteristics and operating characteristics.
In order to eliminate these defects, there are methods to harden the surface of the friction surface, such as carburizing and quenching, tuftride treatment, and ion nitriding treatment, but all of these methods raise the temperature of the entire part. Because it has to be done, the distortion is large,
Therefore, there is a drawback that a re-polishing step is required as a post-process. Furthermore, in the case of carburizing and quenching, the carbon content increases and residual magnetism is generated, which has the disadvantage of making it difficult to cut the brake clutch.

The present invention eliminates the above-mentioned drawbacks by:
To provide an electromagnetic brake/clutch in which the friction surfaces of the armature and magnetic pole are subjected to laser carburizing and quenching to improve wear resistance, extend the life of the electromagnetic brake/clutch, and improve torque characteristics and operating characteristics. The purpose is to

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

In FIG. 2, members 1 to 11 are the same as those shown in the conventional example of FIG. In the conventional configuration, the present invention first prevents laser reflection and produces a carburizing effect on one or both opposing friction surfaces of the armature 4 and the outer and inner magnetic poles 6a and 6b. After a black film treatment is performed using a substance that is made of carbon dioxide, laser irradiation is performed, and surface carburized and hardened layers 12a, 12b, 13a, and 13b are formed by laser carburizing and quenching to improve wear resistance and improve torque characteristics and operation. It has improved characteristics.

To form such a laser carburized hardened layer, the following procedure is performed.

First, a substance that prevents laser reflection and produces a carburizing effect (for example, graphite carbon, black magic ink, black paint, etc.) is applied to the friction surfaces of the armature 4 and the outer and inner magnetic poles 6a and 6b to form a black coating. Perform processing. Next, laser irradiation is performed, and the method will be explained using an armature as an example. Since it is difficult to change the laser irradiation position, the laser is always irradiated at a fixed position, and the armature is continuously rotated to irradiate the laser locally over the required width of the friction surface. Stop.
Such laser irradiation raises the surface temperature of the pure iron or low carbon steel that constitutes the armature to a high temperature below the melting point, and the crystal structure becomes an austenite structure. Furthermore, due to the high temperature, the black coating thermally decomposes to generate carbon, which diffuses into the armature and carburizes it. With this irradiation method, heat is conducted to the non-irradiated parts of the armature, the irradiated parts are rapidly cooled, and together with the hardening effect of thermal stress caused by the rapid cooling, the carburized part undergoes crystal transformation from an austenitic structure to a martensitic structure. Surface carburized hardened layer 12a, 1
2b is formed.

As described above, in the laser hardening process, the workpiece is self-cooled by heat conduction, so the water hardening and oil hardening steps required in normal heat treatment methods can be omitted. In addition, the quenching and hardening time is very short, and it is possible to prevent deterioration and thermal deformation of the base material structure in the non-hardened portion. Furthermore, since laser hardening is a short-time process, the carburizing depth is shallow and the carbon concentration is lower than that of normal carburizing and quenching, so the distortion is small, and there is no need for re-polishing. Since there is little magnetism, it will not make the brake clutch difficult to operate.

Through laser carburizing and quenching as described above,
The hardness of the hardened surface layer of the armature and outer and inner magnetic poles is Bitkers hardness Hv500~600, the depth of the hardened surface layer is 0.1~0.3mm, and the hardness of the base material is Bitkers hardness Hv100~600. 200, the hardened surface layer has a hardness approximately five times that of the base material.

The braking action of the electromagnetic brake of this example is performed in the same way as the conventional one, but since the friction surfaces between the armature and the magnetic pole have the hardness described above, they exhibit extremely good wear resistance, and the electromagnetic brake The lifespan of the product can be extended to about three times that of conventional products. FIG. 3 shows the experimental results of the wear amount of the armature with respect to the number of braking times of the conventional electromagnetic brake A and the electromagnetic brake B whose friction surface of the armature is subjected to laser carburizing and quenching according to the present invention.

Furthermore, by hardening the friction surfaces of the armature and magnetic poles, the amount of wear is reduced, so torque fluctuations are extremely small, exhibiting good torque characteristics and operating characteristics, and stabilizing the braking time. Figure 4 shows a graph of braking torque versus number of brakings, and Figure 5 shows a graph of braking time versus number of brakings for conventional electromagnetic brake A and electromagnetic brake B, in which the friction surface of the armature is subjected to laser carburizing and quenching according to the present invention. Shown below. All of them show good torque characteristics and operating characteristics, especially in the early stages of braking.

In this embodiment, an electromagnetic brake has been described, but an electromagnetic clutch has similar effects.

As described above, the electromagnetic brake/clutch according to the present invention has a carburized and hardened surface layer formed on the opposing friction surfaces of the armature and the outer and inner magnetic poles by laser carburizing and quenching, so it has extremely good wear resistance. It has extremely excellent effects in that it can extend the life of electromagnetic brakes and clutches, and improve torque characteristics and operating characteristics.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional front view of the upper half of an example of a conventional electromagnetic brake, Fig. 2 is a cross-sectional front view of the upper half of an embodiment of the present invention, and Fig. 3 is a conventional electromagnetic brake A and the present invention. FIG. 4 is a graph showing the relationship between the amount of wear on the armature and the number of times of braking with the electromagnetic brake B of the present invention; FIG. The figure is a graph showing the relationship between the number of times of braking and the braking time of the conventional electromagnetic brake A and the electromagnetic brake B of the present invention. 4: armature, 6a: outer magnetic pole, 6b: inner magnetic pole, 12a, 12b, 13a, 13b: hardened surface layer.

Claims (1)

[Claims] 1 After performing a black film treatment on one or both of the friction surfaces of the armature 4 and the outer and inner magnetic poles 6a and 6b using a substance containing carbon, laser carburizing and quenching is performed to form carburized and quenched surface hardening layers 12a and 1.
An electromagnetic brake/clutch characterized in that 2b, 13a, and 13b are formed.